Resolution of images captured by cameras is determined mainly by optical factors and number of pixels on the imaging sensor chip. One common way to get a closer view of an object by a camera is to use optical zoom, where the lens of the camera in front of the imaging sensor is moved to change the magnification of the image. Due to higher costs, larger physical dimensions, and form factor demands, optical zooms are generally not utilized in mobile devices, such as smartphones and tablets. As a result, digital enhancement methods, such as digital zoom, are typically employed to improve object visibility details. Digital zoom technology mainly relies on single frame interpolation techniques. These techniques give users a sense of magnification, yet the actual image resolution remains the same. As a result, objects in the images become larger but their details are not improved, which creates pixilated and unclear image results.
In mobile photography, multiple frame technologies improve the resulting quality of captured photographs allowing improved signal-to-noise ratio and enhanced detail, which allows for a high quality digital zoom. Capturing the same scene multiple times within a short time period gives more information that can be used to render a final output frame. When capturing multiple frames with a mobile camera, movement of the camera creates misalignment between captured image frames. Additionally, objects may move while the multiple frames are captured causing a blur of duplicate objects in the final output frame (also known as ghosting). Due to very complex nature of possible motions that can be observed in an unrestricted scene, motion estimation frameworks often fail and produce noticeable artifacts in the resultant image.